Rethinking third trimester ultrasound measurements and risk of adverse neonatal outcomes in pregnancies complicated by hyperglycaemia: A retrospective study

Abstract

Antenatal ultrasound is used frequently in pregnancies complicated by hyperglycaemia; however, it is unclear which measurements have the greatest association with adverse neonatal outcomes. Aim:To assess the association between third trimester ultrasound parameters with adverse neonatal outcomes in pregnancies complicated by hyperglycaemia.Method: All pregnant women with gestational or type 2 diabetes who birthed in a regional hospital over 12 months were included. A composite adverse neonatal outcome was defined by one or more: admission to special care nursery, acidosis, hypoglycaemia, jaundice, shoulder dystocia, respiratory distress syndrome or 5-minute Apgar score < 5. Logistic regression was used to determine odds ratios (OR) for an adverse neonatal outcome, according to pre-specified cut points in both lower and upper percentiles of abdominal circumference (AC) and estimated fetal weight (EFW).Results: Of 275 births an adverse outcome occurred in 122 (44%). Unadjusted OR (95% CI) for AC ≤30 th was 3.2 (1.1-8.8) and >95 th percentile was 3.1 (1.5-6.0) compared with the reference group of 31-70 th percentile. Unadjusted OR for EFW ≤30 th was 1.5 (0.7-3.1) and >95 th percentile was 3.0 (1.4-6.3). After adjusting for maternal age, body mass index, diabetes type, ethnicity, gravidity, mode of delivery and gestation at birth the OR (95% CI) were as follows: AC ≤30 th percentile, 3.7 (1.1-12.4);

A Clinical Update on Gestational Diabetes Mellitus

“…Measured fetal abdominal circumference < 90th percentile on 2 ultrasounds at 3- to 4-week intervals has also been shown to provide high reliability in excluding the risk of LGA ( 351 ). Moreover, a recent retrospective study (n = 275) found that estimated fetal weight or abdominal circumference up to the 30th percentile on third trimester ultrasound was associated with a greater risk of adverse neonatal outcomes, comparable to that observed with abdominal circumference or estimated fetal weight > 95th percentile in women with hyperglycemia in pregnancy (including GDM) ( 354 ). These findings suggest the potential utility of fetal biometry at thresholds other than defining SGA or LGA in identifying higher risk pregnancies in GDM.…”

Benefits and harms associated with an increase in gestational diabetes diagnosis in Queensland, Australia: a retrospective cohort comparison of diagnosis rates, outcomes, interventions and medication use for two periods, 2011–2013 and 2016–2018, using a large perinatal database

“…Therefore, it is possible that any potential benefit of decreasing growth for a small number of large babies may be more than offset by disadvantages of decreasing growth for the more numerous normal-sized or small babies. Babies below the 25th–30th percentiles may be at greater risk of morbidity than babies up to the 95th–97th percentile70 71 and the risk of stillbirth is lowest between the 75th and 95th birth weight percentiles but stillbirth rates increase as birth weights decrease 72 73. Infant mortality until 1 year of age is lowest in LGA babies, with mortality rates also increasing as birth weights decrease 74.…”